Tag Archives: epidemiology

If smoking doesn’t kill, Mike Pence, neither does the plague

The Conversation

Simon Chapman, University of Sydney

US Vice President elect Mike Pence (who has been the recipient of funding from Big Tobacco) once famously wrote:

Time for a quick reality check. Despite the hysteria from the political class and the media, smoking doesn’t kill. In fact two out of every three smokers does [sic] not die from smoking-related illness and nine out of ten smokers do not contract lung cancer.

Pence is referring here to what epidemiologists call the “case fatality rate”: the proportion of deaths from a smoking-related illness to the number of new smoking-related illnesses diagnosed. According to him, the case fatality rate for long term smoking was “only” one in three, meaning only one in three long-term smokers die from a smoking-related illness (such as cardiovascular and respiratory diseases, and smoking related cancers), which somehow meant to him smoking doesn’t kill.

By Pence’s reasoning there are many other diseases that “do not kill”. This extensive list of various diseases’ case fatality rates shows many well known highly fatal diseases with case fatality rates lower than 33%.

These include oropharyngeal anthrax (anthrax that manifests in the mouth and throat), yellow fever, treated bubonic plague, diphtheria, meningococcal disease, legionnaires’ disease, dengue fever and untreated typhoid. The 1918 Spanish ‘flu which was estimated to have killed 50-100 million people globally, had a paltry case fatality rate of around 2.5%.

Pence was also wrong about the rate at which smoking kills. A landmark study of over 34,000 British male doctors (females were excluded when the study commenced in 1951 because there were insufficient numbers of women doctors at the time) has long been the benchmark for the risks of long term smoking.

When the study reported its 50 year follow-up of the cohort, it found “the eventual risks vary from about one half to about two thirds” of all doctors who had smoked had died from a tobacco-related disease.

An Australian study of 204,953 people also confirmed the two in three death rate from smoking.

Today smoking kills some six million people a year globally, and will kill one billion people this century if present trends continue.

The US is the only significant country to have not ratified the World Health Organisation’s Framework Convention on Tobacco Control (the US tends to not sign global treaties). Under a Trump administration, will we see the end of regulation and strict marketing protocols? Will the US be the only nation to ever see a rise in smoking rates after decades of continual falls?

The ConversationSimon Chapman, Emeritus Professor in Public Health, University of Sydney

This article was originally published on The Conversation. (Reblogged by permission). Read the original article.

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Mobile phone health alarmists bereft of credible arguments

The Conversation
Simon Chapman, University of Sydney

In May this year, I led a paper published in Cancer Epidemiology, which looked at the incidence of brain cancer in Australia between 1982 and 2012.

The first mobile phone call was made in Australia in 1987 and today their use is all but universal.

Cancer is a notifiable disease: all newly diagnosed cases are gathered from doctors by state cancer registries and nationally aggregated by the Australian Institute of Health and Welfare in publicly available data.

I summarised our study in this column, which to date has had more than 44,700 readers.


New study: no increase in brain cancer across 29 years of mobile use in Australia


We found that with extremely high proportions of the population having used mobile phones across some 20-plus years (from about 9% in 1993 to about 90% today), age-adjusted brain cancer rates have flatlined over nearly 30 years.

There were significant increases in brain cancer incidence only in those aged 70 years or more. But the increase in this age group began from 1982, before the introduction of mobile phones in 1987 and so cannot be explained by it.

The most likely explanation of the rise in this older age group was improved diagnosis that happened with the introduction of imaging machines that (for example) could more accurately diagnose some strokes as brain cancers.

In the days and weeks after publication, our paper received massive global news and social media attention, achieving an Altmetric score of 835. On the basis of the most media-covered research in all fields in 2015, this would have put it just outside the 100 highest Altmetric scores if we’d published it last year (2016 figures are published early next year).

It also drew the ire of the close-knit international network of mobile phone and wifi alarmists, who are utterly convinced mobile phones are deadly and won’t hear otherwise. Their opening salvo was to accuse me of being an undeclared phone industry stooge.

In 1997 I had been given a small grant by AMTA, the Australian Mobile Telephone Association, to conduct a national survey of how many mobile phone users had ever used their phone to call emergency services such as ambulance, police and fire. Large proportions of people had done so, probably saving many lives by alerting these services far more quickly than when having to find a landline.

I didn’t report this because I got the one-off grant 19 years ago, and all reputable journals and research agencies rule that competing interests are not lifetime but extinguish typically between one and three years after such support has expired. The grant also had nothing to do with cancer.

I also got a series of mostly verbally incontinent email. One from an excitable correspondent in Swaziland, insisted that I answer his many eureka moment insights into why what we had published was wrong in every respect. We should withdraw our paper, he demanded and tell the world we were wrong.

Predictably, several wrote to Cancer Epidemiology, setting out a litany of our egregious errors and failures to understand that an epidemic of brain cancer, comparable to the deluge of smoking-caused cancers, was just around the corner. Three of these were published this week with our response (open access until October 20, 2016).

The three letters were written by five individuals, three of whom are affiliated with a non-accredited Environmental Health Trust, headed by Dr Devra Davis, the alarmist doomsayer who featured in the much-criticised ABC Catalyst program which has now been withdrawn.

Assuming they got their heads together to rain blows on our heretical findings, it was amusing to see the barely audible blanks they decided to fire.

Their main arguments were:

‘It’s too soon to see an epidemic of brain cancer’

One argued several decades of widespread phone use were needed before increases in cancer might be seen. She seemed intent on diminishing the number of years that large numbers of Australians have used mobile phones, in order to preserve her argument. She argued that only the last nine years of data since 2001 when mobile subscriptions reached 50% of the population ought to be considered in any analysis. And nine years was not nearly enough.

But by 1996, some 20% of Australian adults (some 2.9 million) were using mobile phones. Apparently we ought to have joined her in seeing this as a trivial exposed population, unworthy of consideration. Quite obviously, there’s no alleged carcinogen where 20% of the population is exposed where any credible scientist would seriously maintain such widespread exposure should be ignored in assessing population attributable risk.

Further, in one of the studies cited in a review published by our critics, excess risks of brain cancer from mobile phone use are argued as occurring following exposures of as little as between five and ten years of mobile phone use. These critics even suggested in the same paper that the international INTERPHONE study may suggest a cancer “promotion effect”, with use as few as one to four years being dangerous.

We concluded that:

This therefore looks like an argument trying to walk on both sides of the street: if a short latency period show excess risks they are deemed to be credible, while if they show no excess (as with our study) they are to be dismissed.

‘Various case-control studies show evidence of increased risk’

Case-control studies in this field have been criticised because they rely on users’ recall of the extent of phone use going back many years. Just try recall your own mobile phone use in, for example, 2003 and you will immediately understand how data obtained this way are hugely problematic.

Moreover, people with brain cancer often have memory loss. And if you have brain cancer, are part of a study considering its cause, and have been exposed to frequent claims about the hypothesis that mobile phone use causing brain cancer, the likelihood of recall bias resulting in recall of high mobile phone use is probably going to increase.

The strength of our study was the ability to look at all cases of brain cancer in Australia in the 29 years since the first call was made here. The inconvenient fact for the alarmists is that there has been no significant increase in brain cancer in either men or women compatible with the mobile phone hypothesis.

‘Decreased use of X-rays is masking an increase in cancers caused by mobiles’

Perhaps the silliest argument thrown at us was an unreferenced hypothesis that “discontinued or reduced use of established carcinogens such as X-rays” may have reduced the incidence of brain cancer from such exposures while, simultaneously, the rise of mobile phone use would have replaced those cases, thereby explaining the largely flat line incidence across our data period.

This hypothesis would need to account for how reductions in a very uncommon radiation exposure (full head X-rays) could ever possibly produce the exact same decreased incidence of brain cancer that they claim arise in daily exposure to an alleged carcinogen by most of the entire population would add to that incidence.

Our Swaziland critic finished one of his missives writing that “it behooves you, as a scientist, to take note of fatal errors in your work.” It would “behoove” mobile phone alarmists to stop unnecessarily alarming people with their weak arguments.

The ConversationSimon Chapman, Emeritus Professor in Public Health, University of Sydney

This article was originally published on The Conversation. (Reblogged by permission). Read the original article.
 

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The slow-burn, devastating impact of tobacco plain packs

The Conversation

Simon Chapman, University of Sydney

It is three years since Australia fully implemented its historic tobacco plain packaging law. From December 1, 2012, all tobacco products have been required to be sold in the mandated standardised packs, which, with their large disturbing graphic health warnings, are anything but “plain”.

Ever since, there have been frenzied efforts by the tobacco industry and its ideological baggage carriers to discredit the policy as a failure.

The obvious subtext of this effort has been to megaphone a message to other governments that they should not contemplate introducing plain packaging because it has “failed”: smoking, it is claimed, has not fallen any faster in Australia after plain packaging that it was already falling before. All that has occurred, they argue, is that illicit trade has increased.

The supreme irony here is of course that if such criticism was correct, then to paraphrase Hamlet’s mother Gertrude, “The tobacco industry doth protest too much, methinks.” Why would the industry and its astro-turfed bloggers waste so much money and effort denigrating a policy which was having little or no impact?

Why take the Australian government to the High Court (and fail six to one) to try and block the law? Why invest in supporting minnow tobacco-growing states such as the Dominican Republic, Honduras and Cuba in their efforts to have the World Trade Organization rule against plain packaging?

Why not just ignore an ineffective policy instead of making it only too obvious to all by such actions that it is in fact a grave threat to your industry?

Two key assumptions have underscored efforts to discredit the impact of plain packaging. First, critics assume the impacts of the law should have been evident immediately as it was implemented: as one colleague put it recently “within ten seconds of the law passing”.

Second, they assume (but never actually state) that the impact of plain packaging on smoking by children (the principal target) and adults was supposedly going to be greater than anything we have previously observed in the entire history of tobacco control.

In 1999, the late Tony McMichael, professor of epidemiology at the Australian National University, published a classic paper called Prisoners of the Proximate where he wrote about the need to understand the determinants of population health in terms that extend beyond proximate single risk factors and influences.

In tobacco control, both proximal (discrete, recent and quick-acting) and distal (on-going, slow-burn) effects of policies and campaigns can occur.
Price rises (and falls through discounting) can have both immediate and lasting effects, jolting smokers into sometimes unplanned quitting and also slowly percolating an unease about the costs of smoking that translate into quitting down the track.

Tobacco advertising bans are a good example of a policy that has such slow-burn effects across many years. Few if any quit smoking in direct response to tobacco advertising bans. They work instead by causing the next generations of kids to grow up in an environment devoid of massive promotional campaigns depicting smoking in positive ways.

I have often heard smokers say “plain packaging won’t make me quit smoking”. This is akin to the myopic self-awareness of those who swear “advertising (for any product) never influences me” while noting that it only influences the more impressionable.

Plain packs were unlikely to act suddenly in the way tax rises do, although the unavoidably huge graphic health warnings may well have acted like straws that broke the Camel’s back of worry about smoking. Their impact was far more likely to be of the slow-burn sort, where the constant reminder that tobacco, unique among all products, is the only consumer good treated this way by the law. It is exceptionally dangerous, with a recent estimate that two in every three long-term smokers will die from tobacco use.

In 1994 I wrote a now highly cited paper in the British Medical Journal which talked about the impossibility of “unravelling gossamer with boxing gloves” when it came to being certain about precisely why smokers quit. I took a day in the life of a smoker who quit, and pointed to the myriad of influences both distal and proximal that coalesce to finally stimulate a smoker to quit.

While a smoker might nominate a particular policy, conversation with a doctor or anti-smoking campaign as being “the reason” they quit, much of what went on before provides the broad shoulders of concern that carry the final attribution. There are synergies between all these factors and the demand to separate them all is like the demand to unscramble an omelette.

So what has happened to smoking in Australia since plain packs?

Data released this month from a national schools survey involving more than 23,000 high school children found smoking rates were the lowest ever recorded since the studies first commenced in 1984 (see graph). This momentum is starving the tobacco industry of new smokers, which is one important reason why all tobacco companies are now busily acquiring e-cigarette brands.

Proportion of 12- to 15-year-olds who smoke, 1984 to 2014

Trends in proportion of current (smoked in past seven days) and committed smokers (smoked on three or more of the past seven days) among 12 to 15-year old students, Australia, 1984-2014. National Drug Strategy report 2014.

With adults, National Accounts data just released show that for the 11 quarter-year periods since March 2013, consumption of tobacco products in aggregate fell an unprecedented 20.8%, while the previous 11 quarters it fell 15.7% and in the 11 before that, only 2.2%.

The latest available data on adult smoking prevalence we have is from 2013 and shows just 12.8% of Australians over 14 smoked on a daily basis. This is the lowest on record and again, the biggest percentage falls experienced since the surveys commenced (see graph).

Reductions in daily smoking among Australians aged over 14, 1991 to 2013

AIHW National Drug Strategy Household Survey 2013: preliminary findings. 2014 Author-sourced.

Meanwhile, the tobacco industry plods along funding heavily lambasted studies which purport to show none of this is happening.

The argument that plain packaging would cause illicit trade to boom was made with monotonous regularity by Big Tobacco between April 2010 when plain packaging was announced and its December 2012 implementation. When the industry lost its case in the High Court, the argument was quietly dropped.

Today, the industry explains illicit trade entirely by the heinous government tobacco tax rises cloaked in a sanctimonious rhetoric of speaking up for poor smokers and corporate citizen concern about tax avoidance bleeding Treasury. In all this it fails to mention that it has long used tax rises as air cover to quietly raise its own profit margins.

As I wrote recently in The Conversation:

From August 2011 to February 2013, while excise duty rose 24¢ for a pack of 25, the tobacco companies’ portion of the cigarette price (which excludes excise and GST), jumped A$1.75 to A$7.10. While excise had risen 2.8% over the period, the average net price had risen 27%. Philip Morris’ budget brand Choice 25s rose A$1.80 in this period, with only 41¢ of this being from excise and GST.

Ireland, the United Kingdom and France have already passed laws to introduce plain packs. Norway and Canada will soon, and New Zealand, Chile, Turkey, South Africa and Brazil have also made high-level noises about joining in too. The world has a lot to thank Rudd and Gillard governments (and particularly Health Minister Nicola Roxon) for taking this initiative, and the subsequent Coalition government for continuing to support it strongly as it continues to come under attack from those it has and will continue to hurt.

The ConversationSimon Chapman, Professor of Public Health, University of Sydney

This article was originally published on The Conversation. (Reblogged by permission). Read the original article.

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What makes weird beliefs thrive? The epidemiology of pseudoscience

Footnotes to Plato

epidemiologyMaarten Boudry, Stefaan Blancke and yours truly have published a paper on what we call the “epidemiology of pseudoscience.” Here is the abstract, to give you an idea:

What makes beliefs thrive? We model the dissemination of bona fide science versus pseudoscience, making use of Dan Sperber’s epidemiological model of representations. Drawing on cognitive research on the roots of irrational beliefs and the institutional arrangement of science, we explain the dissemination of beliefs in terms of their salience to human cognition and their ability to adapt to specific cultural ecologies.

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